How to avoid fluid appearing outside collision objects?
I can't comment, so:

Try to keep the size of the domain as small as possible, and as fit to the simulation as possible. That makes the simulation require less resolution. For example, if you pour liquid from a bottle into a glass, restrict the boundaries of the domain to the neck of the bottle on top, and on the bottom, to the table, if you wish to have drops fall on the table. The domain works like a third dimension matrix. The resolution allows for the cells that are inside it to be smaller (which gives more resolution) or larger, depending on the resolution. Which is why you must fit your domain to your scene as much as you can. Since the cells inside your domain are not small enough, they touch the glass and some of them leak out, since the cells are larger than the thin glass.

I also suggest that you try to use "volume initialization" set to "shell" on the obstacle fluid properties, which will change a lot of things (although it won't work miracles).

As you already know, the trick about precise liquids is the resolution of the domain. It's the only thing.

One example (Only 102 of resolution and domain subsurf):